Deoxyribonucleic Acid (DNA) sequencing is a process of determining the precise order of nucleotides within a DNA molecule. DNA sequencing includes any technology or method that is used to determine the order of the four nucleobases—adenine, guanine, cytosine, and thymine—in a strand of DNA. The rapid speed of modern DNA sequencing technology has allowed the sequencing of complete DNA sequences, or genomes of numerous types and species of life, including the human genome and other complete DNA sequences of many animal, plant, and microbial species.